5,854 research outputs found
Evaluation Methodologies in Software Protection Research
Man-at-the-end (MATE) attackers have full control over the system on which
the attacked software runs, and try to break the confidentiality or integrity
of assets embedded in the software. Both companies and malware authors want to
prevent such attacks. This has driven an arms race between attackers and
defenders, resulting in a plethora of different protection and analysis
methods. However, it remains difficult to measure the strength of protections
because MATE attackers can reach their goals in many different ways and a
universally accepted evaluation methodology does not exist. This survey
systematically reviews the evaluation methodologies of papers on obfuscation, a
major class of protections against MATE attacks. For 572 papers, we collected
113 aspects of their evaluation methodologies, ranging from sample set types
and sizes, over sample treatment, to performed measurements. We provide
detailed insights into how the academic state of the art evaluates both the
protections and analyses thereon. In summary, there is a clear need for better
evaluation methodologies. We identify nine challenges for software protection
evaluations, which represent threats to the validity, reproducibility, and
interpretation of research results in the context of MATE attacks
Approximate Computing Survey, Part I: Terminology and Software & Hardware Approximation Techniques
The rapid growth of demanding applications in domains applying multimedia
processing and machine learning has marked a new era for edge and cloud
computing. These applications involve massive data and compute-intensive tasks,
and thus, typical computing paradigms in embedded systems and data centers are
stressed to meet the worldwide demand for high performance. Concurrently, the
landscape of the semiconductor field in the last 15 years has constituted power
as a first-class design concern. As a result, the community of computing
systems is forced to find alternative design approaches to facilitate
high-performance and/or power-efficient computing. Among the examined
solutions, Approximate Computing has attracted an ever-increasing interest,
with research works applying approximations across the entire traditional
computing stack, i.e., at software, hardware, and architectural levels. Over
the last decade, there is a plethora of approximation techniques in software
(programs, frameworks, compilers, runtimes, languages), hardware (circuits,
accelerators), and architectures (processors, memories). The current article is
Part I of our comprehensive survey on Approximate Computing, and it reviews its
motivation, terminology and principles, as well it classifies and presents the
technical details of the state-of-the-art software and hardware approximation
techniques.Comment: Under Review at ACM Computing Survey
ABC: Adaptive, Biomimetic, Configurable Robots for Smart Farms - From Cereal Phenotyping to Soft Fruit Harvesting
Currently, numerous factors, such as demographics, migration patterns, and economics, are leading to the critical labour shortage in low-skilled and physically demanding parts of agriculture. Thus, robotics can be developed for the agricultural sector to address these shortages. This study aims to develop an adaptive, biomimetic, and configurable modular robotics architecture that can be applied to multiple tasks (e.g., phenotyping, cutting, and picking), various crop varieties (e.g., wheat, strawberry, and tomato) and growing conditions. These robotic solutions cover the entire perceptionâactionâdecision-making loop targeting the phenotyping of cereals and harvesting fruits in a natural environment.
The primary contributions of this thesis are as follows. a) A high-throughput method for imaging field-grown wheat in three dimensions, along with an accompanying unsupervised measuring method for obtaining individual wheat spike data are presented. The unsupervised method analyses the 3D point cloud of each trial plot, containing hundreds of wheat spikes, and calculates the average size of the wheat spike and total spike volume per plot. Experimental results reveal that the proposed algorithm can effectively identify spikes from wheat crops and individual spikes. b) Unlike cereal, soft fruit is typically harvested by manual selection and picking. To enable robotic harvesting, the initial perception system uses conditional generative adversarial networks to identify ripe fruits using synthetic data. To determine whether the strawberry is surrounded by obstacles, a cluster complexity-based perception system is further developed to classify the harvesting complexity of ripe strawberries. c) Once the harvest-ready fruit is localised using point cloud data generated by a stereo camera, the platformâs action system can coordinate the arm to reach/cut the stem using the passive motion paradigm framework, as inspired by studies on neural control of movement in the brain. Results from field trials for strawberry detection, reaching/cutting the stem of the fruit with a mean error of less than 3 mm, and extension to analysing complex canopy structures/bimanual coordination (searching/picking) are presented.
Although this thesis focuses on strawberry harvesting, ongoing research is heading toward adapting the architecture to other crops. The agricultural food industry remains a labour-intensive sector with a low margin, and cost- and time-efficiency business model. The concepts presented herein can serve as a reference for future agricultural robots that are adaptive, biomimetic, and configurable
Advances in Methane Production from Coal, Shale and Other Tight Rocks
This collection reports on the state of the art in fundamental discipline application in hydrocarbon production and associated challenges in geoengineering activities. Zheng et al. (2022) report an NMR-based method for multiphase methane characterization in coals. Wang et al. (2022) studied the genesis of bedding fractures in Ordovician to Silurian marine shale in the Sichuan basin. Kang et al. (2022) proposed research focusing on the prediction of shale gas production from horizontal wells. Liang et al. (2022) studied the pore structure of marine shale by adsorption method in terms of molecular interaction. Zhang et al. (2022) focus on the coal measures sandstones in the Xishanyao Formation, southern Junggar Basin, and the sandstone diagenetic characteristics are fully revealed. Yao et al. (2022) report the source-to-sink system in the Ledong submarine channel and the Dongfang submarine fan in the Yinggehai Basin, South China Sea. There are four papers focusing on the technologies associated with hydrocarbon productions. Wang et al. (2022) reported the analysis of pre-stack inversion in a carbonate karst reservoir. Chen et al. (2022) conducted an inversion study on the parameters of cascade coexisting gas-bearing reservoirs in coal measures in Huainan. To ensure the safety CCS, Zhang et al (2022) report their analysis of available conditions for InSAR surface deformation monitoring. Additionally, to ensure production safety in coal mines, Zhang et al. (2022) report the properties and application of gel materials for coal gangue control
Library Screening and Focused Multiomics of Antibacterial Action on Vancomycin-Resistant Enterococci faecium
Title from PDF of title page, viewed July 5, 2023Dissertation advisor: William GutheilVitaIncludes bibliographical references (pages 228-257)Dissertation (Ph.D.)--Division of Pharmaceutical Sciences, Department of Chemistry. University of Missouri--Kansas City, 2023Antimicrobial resistance is a major public health threat, and there is an urgent need for new strategies to address this issue. In a gram-positive bacteria, the peptidoglycan layer is thick as compared to gram negatives and is made up of peptide like polysaccharide chains. This peptidoglycan layer is a target for many antibiotics to inhibit bacteria. Enterococcus species are gram-positive bacteria of the intestine in humans and animals that can lead to problematic infections of the gastrointestinal tract and the soft tissues. Vancomycin has been one of most important agents for the treatment of gram-positive bacterial infections. The emergence and spread of vancomycin resistance has become a serious public health issue and vancomycin resistant bacteria are worldâs highest priority pathogen according to WHO. Resistance in VanA-type vancomycin-resistant Enterococcus faecium (VREfm) is due to an inducible gene cassette encoding seven proteins (vanRSHAXYZ). This provides for an alternative peptidoglycan (PG) biosynthesis pathway whereby D-Alanine-D-Alanine is replaced by D-Alanine-D-Lactate (Lac), to which vancomycin cannot bind effectively. While the general features of this resistance mechanism are well known, the details of the choreography between vancomycin exposure, vanA gene induction, and changes in the normal and alternative pathway intermediate levels have not been described previously.
Part I of my dissertation describes quantifying the cytoplasmic levels of normal and alternative pathway PG intermediates in VanA-type VRE faecium (VREfm) by liquid chromatography-tandem mass spectrometry before and after vancomycin exposure and to correlate these changes with changes in vanA operon mRNA levels measured by real-time quantitative PCR (RT-qPCR). Normal pathway intermediates in VREfm predominate in the absence of vancomycin, with low basal levels of alternative pathway intermediates. RT-qPCR demonstrated that vanA operon mRNA transcript levels increase rapidly after exposure, reaching maximal levels in 15 minutes. To resolve the effect of increased van operon protein expression on PG metabolite levels, linezolid was used to block protein biosynthesis. Surprisingly, linezolid dramatically reduced PG intermediate levels when used alone. When used in combination with vancomycin, linezolid only modestly reduced alternative UDP-linked PG intermediate levels, indicating substantial alternative pathway presence before vancomycin exposure. Comparison of PG intermediate levels between VRE faecium, vancomycin-sensitive Enterococcus faecium, and methicillin-resistant Staphylococcus aureus after vancomycin exposure demonstrated substantial differences between S. aureus and E. faecium.
Part II of my thesis describes developing a two-dimensional chemical compound library screening strategy. The first screening was done using an FDA approved drug library that was screened against vancomycin-resistant Enterococcus faecium (VREfm) in both its original (unmetabolized; UM) and its microsome metabolized (pre-metabolized; PM) forms, and in the absence and presence of vancomycin. This allows the identification of agents with active metabolites and agents that can act synergistically with the resistant-to-antibiotic. 2 x 2 experimental design library screening was also done using NCI diversity set V against both Methicillin-resistant Staphylococcus aureus (MRSA) in absence and presence of cefoxitin and against VRE faecium in absence and presence of vancomycin. The synergistic combinations of all the actives obtained after the screen can be used for in-vitro studies in future as it helps in the reduction the dose when combined. This can help in minimizing the side effects of high concentrations of drugs.
Part III of my dissertation describes experiments like active versus active where the active hits obtained after screening results were further combined to look for synergistic and antagonistic combinations. The other experiment was to look at the mechanism of action of various drugs against VRE faecium. As previously described, many resistant genes are involved in the resistance pathway of VREfm. When VREfm was treated with these antibiotics, the resistance genes were induced which showed the presence of resistance in VRE faecium. Therefore, gene induction was observed using both low (1/4th x MIC) and high (4x MIC) of an antibiotic. Furthermore, mutagenesis study was also done using MRSA. In this study, mutants of MRSA were generated on resistant antibiotic plates. It was followed by the extraction of genomic DNA which was later used to study whole genome sequence of MRSA. This study helped us to identify the mutation causing genes. This experiment can further be used for VRE faecium and gram-negatives.Focused metabolomics, proteomics and transcriptomics of VanA-type vamcomycin resistant enterococcus faecium -- Chemical library screening for new antibacterial drug discovery -- Drug interactions and whole genome sequencing of resistant bacteri
Operatic Pasticcios in 18th-Century Europe
In Early Modern times, techniques of assembling, compiling and arranging pre-existing material were part of the established working methods in many arts. In the world of 18th-century opera, such practices ensured that operas could become a commercial success because the substitution or compilation of arias fitting the singer's abilities proved the best recipe for fulfilling the expectations of audiences. Known as »pasticcios« since the 18th-century, these operas have long been considered inferior patchwork. The volume collects essays that reconsider the pasticcio, contextualize it, define its preconditions, look at its material aspects and uncover its aesthetical principles
Genomic Analysis of Antibiotics Resistance in Pathogens
The emergence of antibiotic-resistant pathogens currently represents a serious threat to public health and the economy. Due to antibiotic treatments in humans and veterinary medicine, prophylactic use and environmental contamination, bacteria are today more frequently exposed to unnatural doses of antibiotics and their selective effect.Antibiotic resistance can be encoded on chromosomes, plasmids, or other mobile genetic elements in bacteria. It may also result from mutations that lead to changes in the affinity of antibiotics for their targets or in the ability of antibiotics to act on bacterial growth or death. Exposure of bacteria, bacterial populations, and microbial communities to antibiotics at different concentrations shapes their genomic dynamics, as does the mobilisation and spread of resistance determinants. It is, therefore, essential to understand the dynamics and mobilisation of genes encoding antibiotic resistance, in human, animal, plant, and environmental microbiomes, through genomic and metagenomic approaches and bioinformatics analyses.This Special Issue gathers research publications on the horizontal transfer of antibiotic-resistance genes, their dissemination and epidemiology, their association with bacterial virulence, between bacterial genotypes and their phenotypes, and other related research topics
Land Use and Land Cover Mapping in a Changing World
It is increasingly being recognized that land use and land cover changes driven by anthropogenic pressures are impacting terrestrial and aquatic ecosystems and their services, human society, and human livelihoods and well-being. This Special Issue contains 12 original papers covering various issues related to land use and land use changes in various parts of the world (see references), with the purpose of providing a forum to exchange ideas and progress in related areas. Research topics include land use targets, dynamic modelling and mapping using satellite images, pressures from energy production, deforestation, impacts on ecosystem services, aboveground biomass evaluation, and investigations on libraries of legends and classiïŹcation systems
Big Data and Analytics: Issues and Challenges for the Past and Next Ten Years
In this paper we continue the minitrack series of papers recognizing issues and challenges identified in the field of Big Data and Analytics, from the past and going forward. As this field has evolved, it has begun to encompass other analytical regimes, notably AI/ML systems. In this paper we focus on two areas: continuing main issues for which some progress has been made and new and emerging issues which we believe form the basis for near-term and future research in Big Data and Analytics. The Bottom Line: Big Data and Analytics is healthy, is growing in scope and evolving in capability, and is finding applicability in more problem domains than ever before
Human-Centered Approach to Technology to Combat Human Trafficking
Human trafficking is a serious crime that continues to plague the United States. With the rise of computing technologies, the internet has become one of the main mediums through which this crime is facilitated. Fortunately, these online activities leave traces which are invaluable to law enforcement agencies trying to stop human trafficking. However, identifying and intervening with these cases is still a challenging task. The sheer volume of online activity makes it difficult for law enforcement to efficiently identify any potential leads. To compound this issue, traffickers are constantly changing their techniques online to evade detection. Thus, there is a need for tools to efficiently sift through all this online data and narrow down the number of potential leads that a law enforcement agency can deal with. While some tools and prior research do exist for this purpose, none of these tools adequately address law enforcement user needs for information visualizations and spatiotemporal analysis. Thus to address these gaps, this thesis contributes an empirical study of technology and human trafficking. Through in-depth qualitative interviews, systemic literature analysis, and a user-centered design study, this research outlines the challenges and design considerations for developing sociotechnical tools for anti-trafficking efforts. This work further contributes to the greater understanding of the prosecution efforts within the anti-trafficking domain and concludes with the development of a visual analytics prototype that incorporates these design considerations.Ph.D
- âŠ